The accessory belt has been noisy and a lot of movement in the tensioner at idle on my 07 TD4. I found that the alternator pulley which has a one way clutch in it had seized.
If anyone is chasing a noisy belt on a TD4 this may help
LR will only sell you a new alternator but the pulley is available.
This is the one I purchased

Alternator Overrunning Pulley Land Rover Freelander 2 LF 224DT | eBay

You will also need this tool to fit.

Audi VW Golf Passat Free Wheeling V Belt Pulley Removal Alternator Socket Tool | eBay

Yes its a VW one but it fits and works.